Verwenden von AWS SDK zur Konfiguration von Auto Scaling in Amazon DynamoDB-Tabellen

Zusätzlich zur Verwendung von AWS Management Console und AWS Command Line Interface (AWS CLI) können Sie Anwendungen schreiben, die mit Amazon DynamoDB Auto Scaling interagieren. Dieser Abschnitt enthält zwei Java-Programme, die Sie verwenden können, um diese Funktionalität zu testen:

• EnableDynamoDBAutoscaling.java

• DisableDynamoDBAutoscaling.java

Aktivieren von Application Auto Scaling für eine Tabelle

Das folgende Programm zeigt ein Beispiel für die Einrichtung einer Auto-Scaling-Richtlinie für eine DynamoDB-Tabelle (TestTable). Es fährt wie folgt fort:

• Das Programm registriert Schreibkapazitätseinheiten als skalierbares Ziel für TestTable. Der Bereich für diese Metrik liegt zwischen 5 und 10 Schreibkapazitätseinheiten.

• Nachdem das skalierbare Ziel erstellt wird, erstellt das Programm eine Ziel-Tracking-Konfiguration. Die Richtlinie versucht ein 50 %-Zielverhältnis zwischen verbrauchter und bereitgestellter Schreibkapazität beizubehalten.

• Das Programm erstellt dann die Skalierungsrichtlinie, basierend auf der Ziel-Tracking-Konfiguration.

Anmerkung

Wenn Sie eine Tabelle oder ein globales Tabellenreplikat manuell entfernen, entfernen Sie nicht automatisch alle zugehörigen skalierbaren Ziele, Skalierungsrichtlinien oder Alarme. CloudWatch

Java v2

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.applicationautoscaling.ApplicationAutoScalingClient;
import software.amazon.awssdk.services.applicationautoscaling.model.ApplicationAutoScalingException;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalableTargetsRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalableTargetsResponse;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalingPoliciesRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalingPoliciesResponse;
import software.amazon.awssdk.services.applicationautoscaling.model.PolicyType;
import software.amazon.awssdk.services.applicationautoscaling.model.PredefinedMetricSpecification;
import software.amazon.awssdk.services.applicationautoscaling.model.PutScalingPolicyRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.RegisterScalableTargetRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.ScalingPolicy;
import software.amazon.awssdk.services.applicationautoscaling.model.ServiceNamespace;
import software.amazon.awssdk.services.applicationautoscaling.model.ScalableDimension;
import software.amazon.awssdk.services.applicationautoscaling.model.MetricType;
import software.amazon.awssdk.services.applicationautoscaling.model.TargetTrackingScalingPolicyConfiguration;
import java.util.List;

/**
 * Before running this Java V2 code example, set up your development environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */
public class EnableDynamoDBAutoscaling {
    public static void main(String[] args) {
        final String usage = """

            Usage:
               <tableId> <roleARN> <policyName>\s

            Where:
               tableId - The table Id value (for example, table/Music).
               roleARN - The ARN of the role that has ApplicationAutoScaling permissions.
               policyName - The name of the policy to create.
               
            """;

        if (args.length != 3) {
            System.out.println(usage);
            System.exit(1);
        }

        System.out.println("This example registers an Amazon DynamoDB table, which is the resource to scale.");
        String tableId = args[0];
        String roleARN = args[1];
        String policyName = args[2];
        ServiceNamespace ns = ServiceNamespace.DYNAMODB;
        ScalableDimension tableWCUs = ScalableDimension.DYNAMODB_TABLE_WRITE_CAPACITY_UNITS;
        ApplicationAutoScalingClient appAutoScalingClient = ApplicationAutoScalingClient.builder()
            .region(Region.US_EAST_1)
            .build();

        registerScalableTarget(appAutoScalingClient, tableId, roleARN, ns, tableWCUs);
        verifyTarget(appAutoScalingClient, tableId, ns, tableWCUs);
        configureScalingPolicy(appAutoScalingClient, tableId, ns, tableWCUs, policyName);
    }

    public static void registerScalableTarget(ApplicationAutoScalingClient appAutoScalingClient, String tableId, String roleARN, ServiceNamespace ns, ScalableDimension tableWCUs) {
        try {
            RegisterScalableTargetRequest targetRequest = RegisterScalableTargetRequest.builder()
                .serviceNamespace(ns)
                .scalableDimension(tableWCUs)
                .resourceId(tableId)
                .roleARN(roleARN)
                .minCapacity(5)
                .maxCapacity(10)
                .build();

            appAutoScalingClient.registerScalableTarget(targetRequest);
            System.out.println("You have registered " + tableId);

        } catch (ApplicationAutoScalingException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
        }
    }

    // Verify that the target was created.
    public static void verifyTarget(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs) {
        DescribeScalableTargetsRequest dscRequest = DescribeScalableTargetsRequest.builder()
            .scalableDimension(tableWCUs)
            .serviceNamespace(ns)
            .resourceIds(tableId)
            .build();

        DescribeScalableTargetsResponse response = appAutoScalingClient.describeScalableTargets(dscRequest);
        System.out.println("DescribeScalableTargets result: ");
        System.out.println(response);
    }

    // Configure a scaling policy.
    public static void configureScalingPolicy(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs, String policyName) {
        // Check if the policy exists before creating a new one.
        DescribeScalingPoliciesResponse describeScalingPoliciesResponse = appAutoScalingClient.describeScalingPolicies(DescribeScalingPoliciesRequest.builder()
            .serviceNamespace(ns)
            .resourceId(tableId)
            .scalableDimension(tableWCUs)
            .build());

        if (!describeScalingPoliciesResponse.scalingPolicies().isEmpty()) {
            // If policies exist, consider updating an existing policy instead of creating a new one.
            System.out.println("Policy already exists. Consider updating it instead.");
            List<ScalingPolicy> polList = describeScalingPoliciesResponse.scalingPolicies();
            for (ScalingPolicy pol : polList) {
                System.out.println("Policy name:" +pol.policyName());
            }
        } else {
            // If no policies exist, proceed with creating a new policy.
            PredefinedMetricSpecification specification = PredefinedMetricSpecification.builder()
                .predefinedMetricType(MetricType.DYNAMO_DB_WRITE_CAPACITY_UTILIZATION)
                .build();

            TargetTrackingScalingPolicyConfiguration policyConfiguration = TargetTrackingScalingPolicyConfiguration.builder()
                .predefinedMetricSpecification(specification)
                .targetValue(50.0)
                .scaleInCooldown(60)
                .scaleOutCooldown(60)
                .build();

            PutScalingPolicyRequest putScalingPolicyRequest = PutScalingPolicyRequest.builder()
                .targetTrackingScalingPolicyConfiguration(policyConfiguration)
                .serviceNamespace(ns)
                .scalableDimension(tableWCUs)
                .resourceId(tableId)
                .policyName(policyName)
                .policyType(PolicyType.TARGET_TRACKING_SCALING)
                .build();

            try {
                appAutoScalingClient.putScalingPolicy(putScalingPolicyRequest);
                System.out.println("You have successfully created a scaling policy for an Application Auto Scaling scalable target");
            } catch (ApplicationAutoScalingException e) {
                System.err.println("Error: " + e.awsErrorDetails().errorMessage());
            }
        }
    }
}

Java v1

Das Programm erfordert, dass Sie einen Amazon-Ressourcennamen (ARN) für eine gültige, mit dem Application Auto Scaling-Service verknüpfte Rolle angeben. (Zum Beispiel: arn:aws:iam::122517410325:role/AWSServiceRoleForApplicationAutoScaling_DynamoDBTable.) Ersetzen Sie das Programm im folgenden Programm SERVICE_ROLE_ARN_GOES_HERE durch das aktuelleARN.

package com.amazonaws.codesamples.autoscaling;

import com.amazonaws.services.applicationautoscaling.AWSApplicationAutoScalingClient;
import com.amazonaws.services.applicationautoscaling.AWSApplicationAutoScalingClientBuilder;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalableTargetsRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalableTargetsResult;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalingPoliciesRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalingPoliciesResult;
import com.amazonaws.services.applicationautoscaling.model.MetricType;
import com.amazonaws.services.applicationautoscaling.model.PolicyType;
import com.amazonaws.services.applicationautoscaling.model.PredefinedMetricSpecification;
import com.amazonaws.services.applicationautoscaling.model.PutScalingPolicyRequest;
import com.amazonaws.services.applicationautoscaling.model.RegisterScalableTargetRequest;
import com.amazonaws.services.applicationautoscaling.model.ScalableDimension;
import com.amazonaws.services.applicationautoscaling.model.ServiceNamespace;
import com.amazonaws.services.applicationautoscaling.model.TargetTrackingScalingPolicyConfiguration;

public class EnableDynamoDBAutoscaling {

	static AWSApplicationAutoScalingClient aaClient = (AWSApplicationAutoScalingClient) AWSApplicationAutoScalingClientBuilder
			.standard().build();

	public static void main(String args[]) {

		ServiceNamespace ns = ServiceNamespace.Dynamodb;
		ScalableDimension tableWCUs = ScalableDimension.DynamodbTableWriteCapacityUnits;
		String resourceID = "table/TestTable";

		// Define the scalable target
		RegisterScalableTargetRequest rstRequest = new RegisterScalableTargetRequest()
				.withServiceNamespace(ns)
				.withResourceId(resourceID)
				.withScalableDimension(tableWCUs)
				.withMinCapacity(5)
				.withMaxCapacity(10)
				.withRoleARN("SERVICE_ROLE_ARN_GOES_HERE");

		try {
			aaClient.registerScalableTarget(rstRequest);
		} catch (Exception e) {
			System.err.println("Unable to register scalable target: ");
			System.err.println(e.getMessage());
		}

		// Verify that the target was created
		DescribeScalableTargetsRequest dscRequest = new DescribeScalableTargetsRequest()
				.withServiceNamespace(ns)
				.withScalableDimension(tableWCUs)
				.withResourceIds(resourceID);
		try {
			DescribeScalableTargetsResult dsaResult = aaClient.describeScalableTargets(dscRequest);
			System.out.println("DescribeScalableTargets result: ");
			System.out.println(dsaResult);
			System.out.println();
		} catch (Exception e) {
			System.err.println("Unable to describe scalable target: ");
			System.err.println(e.getMessage());
		}

		System.out.println();

		// Configure a scaling policy
		TargetTrackingScalingPolicyConfiguration targetTrackingScalingPolicyConfiguration = new TargetTrackingScalingPolicyConfiguration()
				.withPredefinedMetricSpecification(
						new PredefinedMetricSpecification()
								.withPredefinedMetricType(MetricType.DynamoDBWriteCapacityUtilization))
				.withTargetValue(50.0)
				.withScaleInCooldown(60)
				.withScaleOutCooldown(60);

		// Create the scaling policy, based on your configuration
		PutScalingPolicyRequest pspRequest = new PutScalingPolicyRequest()
				.withServiceNamespace(ns)
				.withScalableDimension(tableWCUs)
				.withResourceId(resourceID)
				.withPolicyName("MyScalingPolicy")
				.withPolicyType(PolicyType.TargetTrackingScaling)
				.withTargetTrackingScalingPolicyConfiguration(targetTrackingScalingPolicyConfiguration);

		try {
			aaClient.putScalingPolicy(pspRequest);
		} catch (Exception e) {
			System.err.println("Unable to put scaling policy: ");
			System.err.println(e.getMessage());
		}

		// Verify that the scaling policy was created
		DescribeScalingPoliciesRequest dspRequest = new DescribeScalingPoliciesRequest()
				.withServiceNamespace(ns)
				.withScalableDimension(tableWCUs)
				.withResourceId(resourceID);

		try {
			DescribeScalingPoliciesResult dspResult = aaClient.describeScalingPolicies(dspRequest);
			System.out.println("DescribeScalingPolicies result: ");
			System.out.println(dspResult);
		} catch (Exception e) {
			e.printStackTrace();
			System.err.println("Unable to describe scaling policy: ");
			System.err.println(e.getMessage());
		}

	}

}

Deaktivieren der Application Auto Scaling für eine Tabelle

Das folgende Programm macht den vorherigen Prozess rückgängig. Es entfernt die Auto Scaling-Richtlinie und hebt die Registrierung des skalierbaren Ziels auf.

Java v2

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.applicationautoscaling.ApplicationAutoScalingClient;
import software.amazon.awssdk.services.applicationautoscaling.model.ApplicationAutoScalingException;
import software.amazon.awssdk.services.applicationautoscaling.model.DeleteScalingPolicyRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DeregisterScalableTargetRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalableTargetsRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalableTargetsResponse;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalingPoliciesRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalingPoliciesResponse;
import software.amazon.awssdk.services.applicationautoscaling.model.ScalableDimension;
import software.amazon.awssdk.services.applicationautoscaling.model.ServiceNamespace;

/**
 * Before running this Java V2 code example, set up your development environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */

public class DisableDynamoDBAutoscaling {
    public static void main(String[] args) {
        final String usage = """

            Usage:
               <tableId> <policyName>\s

            Where:
               tableId - The table Id value (for example, table/Music).\s
               policyName - The name of the policy (for example, $Music5-scaling-policy). 
        
            """;
        if (args.length != 2) {
            System.out.println(usage);
            System.exit(1);
        }

        ApplicationAutoScalingClient appAutoScalingClient = ApplicationAutoScalingClient.builder()
            .region(Region.US_EAST_1)
            .build();

        ServiceNamespace ns = ServiceNamespace.DYNAMODB;
        ScalableDimension tableWCUs = ScalableDimension.DYNAMODB_TABLE_WRITE_CAPACITY_UNITS;
        String tableId = args[0];
        String policyName = args[1];

        deletePolicy(appAutoScalingClient, policyName, tableWCUs, ns, tableId);
        verifyScalingPolicies(appAutoScalingClient, tableId, ns, tableWCUs);
        deregisterScalableTarget(appAutoScalingClient, tableId, ns, tableWCUs);
        verifyTarget(appAutoScalingClient, tableId, ns, tableWCUs);
    }

    public static void deletePolicy(ApplicationAutoScalingClient appAutoScalingClient, String policyName, ScalableDimension tableWCUs, ServiceNamespace ns, String tableId) {
        try {
            DeleteScalingPolicyRequest delSPRequest = DeleteScalingPolicyRequest.builder()
                .policyName(policyName)
                .scalableDimension(tableWCUs)
                .serviceNamespace(ns)
                .resourceId(tableId)
                .build();

            appAutoScalingClient.deleteScalingPolicy(delSPRequest);
            System.out.println(policyName +" was deleted successfully.");

        } catch (ApplicationAutoScalingException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
        }
    }

    // Verify that the scaling policy was deleted
    public static void verifyScalingPolicies(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs) {
        DescribeScalingPoliciesRequest dscRequest = DescribeScalingPoliciesRequest.builder()
            .scalableDimension(tableWCUs)
            .serviceNamespace(ns)
            .resourceId(tableId)
            .build();

        DescribeScalingPoliciesResponse response = appAutoScalingClient.describeScalingPolicies(dscRequest);
        System.out.println("DescribeScalableTargets result: ");
        System.out.println(response);
    }

    public static void deregisterScalableTarget(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs) {
        try {
            DeregisterScalableTargetRequest targetRequest = DeregisterScalableTargetRequest.builder()
                .scalableDimension(tableWCUs)
                .serviceNamespace(ns)
                .resourceId(tableId)
                .build();

            appAutoScalingClient.deregisterScalableTarget(targetRequest);
            System.out.println("The scalable target was deregistered.");

        } catch (ApplicationAutoScalingException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
        }
    }

    public static void verifyTarget(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs) {
        DescribeScalableTargetsRequest dscRequest = DescribeScalableTargetsRequest.builder()
            .scalableDimension(tableWCUs)
            .serviceNamespace(ns)
            .resourceIds(tableId)
            .build();

        DescribeScalableTargetsResponse response = appAutoScalingClient.describeScalableTargets(dscRequest);
        System.out.println("DescribeScalableTargets result: ");
        System.out.println(response);
    }
}

Java v1

package com.amazonaws.codesamples.autoscaling;

import com.amazonaws.services.applicationautoscaling.AWSApplicationAutoScalingClient;
import com.amazonaws.services.applicationautoscaling.model.DeleteScalingPolicyRequest;
import com.amazonaws.services.applicationautoscaling.model.DeregisterScalableTargetRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalableTargetsRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalableTargetsResult;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalingPoliciesRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalingPoliciesResult;
import com.amazonaws.services.applicationautoscaling.model.ScalableDimension;
import com.amazonaws.services.applicationautoscaling.model.ServiceNamespace;

public class DisableDynamoDBAutoscaling {

	static AWSApplicationAutoScalingClient aaClient = new AWSApplicationAutoScalingClient();

	public static void main(String args[]) {

		ServiceNamespace ns = ServiceNamespace.Dynamodb;
		ScalableDimension tableWCUs = ScalableDimension.DynamodbTableWriteCapacityUnits;
		String resourceID = "table/TestTable";

		// Delete the scaling policy
		DeleteScalingPolicyRequest delSPRequest = new DeleteScalingPolicyRequest()
				.withServiceNamespace(ns)
				.withScalableDimension(tableWCUs)
				.withResourceId(resourceID)
				.withPolicyName("MyScalingPolicy");

		try {
			aaClient.deleteScalingPolicy(delSPRequest);
		} catch (Exception e) {
			System.err.println("Unable to delete scaling policy: ");
			System.err.println(e.getMessage());
		}

		// Verify that the scaling policy was deleted
		DescribeScalingPoliciesRequest descSPRequest = new DescribeScalingPoliciesRequest()
				.withServiceNamespace(ns)
				.withScalableDimension(tableWCUs)
				.withResourceId(resourceID);

		try {
			DescribeScalingPoliciesResult dspResult = aaClient.describeScalingPolicies(descSPRequest);
			System.out.println("DescribeScalingPolicies result: ");
			System.out.println(dspResult);
		} catch (Exception e) {
			e.printStackTrace();
			System.err.println("Unable to describe scaling policy: ");
			System.err.println(e.getMessage());
		}

		System.out.println();

		// Remove the scalable target
		DeregisterScalableTargetRequest delSTRequest = new DeregisterScalableTargetRequest()
				.withServiceNamespace(ns)
				.withScalableDimension(tableWCUs)
				.withResourceId(resourceID);

		try {
			aaClient.deregisterScalableTarget(delSTRequest);
		} catch (Exception e) {
			System.err.println("Unable to deregister scalable target: ");
			System.err.println(e.getMessage());
		}

		// Verify that the scalable target was removed
		DescribeScalableTargetsRequest dscRequest = new DescribeScalableTargetsRequest()
				.withServiceNamespace(ns)
				.withScalableDimension(tableWCUs)
				.withResourceIds(resourceID);

		try {
			DescribeScalableTargetsResult dsaResult = aaClient.describeScalableTargets(dscRequest);
			System.out.println("DescribeScalableTargets result: ");
			System.out.println(dsaResult);
			System.out.println();
		} catch (Exception e) {
			System.err.println("Unable to describe scalable target: ");
			System.err.println(e.getMessage());
		}

	}

}